JP2937818B2 - Method of forming waterproof layer on continuous underground wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a composite waterproof layer formed on the surface of a continuous underground wall such as a continuous cast-in-place reinforced concrete wall or a soil cement column wall built in the sea or underground. .

[0002]

2. Description of the Related Art Conventionally, a method for forming a waterproof layer on an underground structure includes a so-called post-installation method in which a waterproof layer is attached to the outside of the body from the ground side after the construction of the body, and a retaining wall before the body is cast. In general, there is a so-called advance construction method in which a smooth waterproof base surface is formed in advance using the above-mentioned method, and a waterproof layer is closely attached to the base surface.

[0003] On the other hand, the continuous underground wall is originally intended for earth retaining and waterproofing. However, in recent years, the continuous underground wall often plays a role as a part of the structure main body. The work is directly driven into the continuous underground wall and integrated. However, the continuous underground wall varies depending on its scale and construction conditions,
More or less leakage is inevitable. Therefore, it is necessary to form a waterproof layer on the continuous underground wall by any method before the secondary lining. Conventionally, when forming a waterproof layer, a chemical solution is injected into the water leaking point to temporarily stop the water leakage, or while draining and draining with a drain pipe, the surface of the continuous underground wall is sprayed with cement mortar or trowel work It is common to apply a waterproof sheet after making a waterproof base surface by smoothing the surface. As the waterproof sheet, a rubber sheet or a modified asphalt sheet which is relatively soft and has a large elongation is used.

[0004]

In the case where there is no water leakage from the continuous underground wall surface when the waterproof layer is applied, the surface is relatively smooth, and the adhesion of sediment is small, it can be applied by the conventional method.
Such favorable conditions are rather rare. Most continuous underground walls inevitably leak from the wall surface during construction, and have large surface irregularities and steps. Therefore, the conventional method has the following problems, which must be solved.

(1) Even if a chemical solution is injected into a water leak location to temporarily stop the water leak, it is very difficult to stop all the water leak locations merely by changing the water leak location to another location. Even with the method of conducting and draining water, draining and draining water from all leaking points requires not only a great deal of labor and cost, but also it is not easy to make it dry enough to attach a waterproof sheet.

(2) It is very difficult and expensive to repair large irregularities and steps by spraying a cement mortar or ironing work so that a waterproof sheet can be stuck.

(3) The surface of the continuous underground wall looks smooth as a whole, and even if a waterproof sheet can be attached thereto, if there are large irregularities in a portion, the pressure of the secondary lining concrete and the The head pressure increases the risk of the waterproof sheet stretching and breaking or leaking.

(4) The waterproofing sheet is softened by the heat of hardening of the secondary lining concrete, so that the waterproofing sheet is easily extended and breaks, and water leaks easily occur. In addition, unevenness such as a joining step, a jumper, and a crack is inevitable on the secondary lining concrete side. Therefore, there is a possibility that the waterproof layer may be extended due to a long-term head pressure on the ground side and eventually break.

The present invention solves the above problems in order and forms an effective and durable waterproof layer having no danger of breakage on the surface of a continuous underground wall having a large amount of water leakage and a large surface unevenness or a step. The purpose is to do so.

[0010]

SUMMARY OF THE INVENTION The present invention has been made based on the results of a study on the performance of a waterproof sheet in order to achieve the above object.

That is, the present invention uses a high-strength polypropylene-based sheet having a thickness of 0.6 to 2 mm as a core material,
After fixing a waterproof sheet laminated with rubber asphalt of about mm to the surface of the continuous underground wall, a concrete layer for secondary lining is cast on the surface of the waterproof sheet, and the waterproof layer to the continuous underground wall is characterized in that It is a forming method.

The waterproof sheet used in the present invention will be described.

The waterproof sheet is composed of a core material, which is a high-strength polypropylene sheet having a thickness of 0.6 to 2 mm, and three layers of rubber asphalt having a thickness of about 1 mm laminated on both surfaces thereof.

The polypropylene-based sheet as the core material is required to have mechanical strength and water-blocking properties, as well as adhesion to rubber asphalt, weather resistance, heat resistance, economy, and the like. Furthermore, in the construction of the present invention, it is required to supply a long waterproof sheet as a large roll, and the core material is required to be rollable and have some flexibility. In the present invention,
From these required characteristics, a polypropylene-based sheet having a thickness of 0.6 to 2 mm was selected as a core material. The polypropylene-based sheet includes not only those manufactured from polypropylene, but also commercially available sheets manufactured from a synthetic resin obtained by mixing an appropriate amount of a modifying agent with polypropylene, and commercially available sheets having a modified surface to improve adhesion. . Polypropylene-based sheet is hard, it can not be said that it is rich in flexibility, and the thinner the thickness, the lower the mechanical strength, but if the above thickness of about 0.6 to 2 mm, Not only does it sufficiently satisfy the required mechanical strength, it can be rolled and unrolled with the laminated rubber asphalt, and does not hinder transport or construction.

As the rubber asphalt to be laminated with the polypropylene-based sheet as the core material, a normal asphalt having improved adhesiveness and extensibility by adding various synthetic rubbers and sometimes a synthetic resin to the asphalt is used. The rubber asphalt layer is formed to a thickness of about 1 mm, and the laminated waterproof sheet is wound into a roll and provided for transportation and construction.

A general construction method for forming a waterproof layer on a continuous underground wall using the above-mentioned roll-shaped waterproof sheet will be described.

(1) A waterproof sheet is fixed to the surface of the continuous underground wall.

First, one end of the waterproof sheet is fixed to the upper end surface of the continuous underground wall with nails, nails or anchors. Next, the roll of the waterproof sheet is unwound, and the waterproof sheet is sequentially attached from the upper end to the lower end of the continuous underground wall while peeling off the release paper of the rubber asphalt layer on the outer surface of the waterproof sheet. In attaching the second and subsequent sheets, the waterproof sheets are joined to each other by bonding or welding with the overlap width being about 100 mm.

Also, nails and tacks may be used at the joint. For nails, studs and joints, caulking treatment or reinforcement with a sheet having strong adhesiveness may be performed.

The water leaking from the continuous underground wall is guided downward along the outside of the waterproof sheet, and is drained out of the site by a pump.

(2) Next, as usual, a formwork is assembled on the inside of the waterproof sheet, the concrete is laid and the concrete is poured to construct a reinforced concrete for secondary lining.

When the concrete for the secondary lining is cast, the waterproof sheet is integrated with the concrete and supported in a form sandwiched between the concrete and the continuous underground wall. Due to the pressure, it slightly deforms to the concave side of the outer continuous underground wall, but the deformation is not large, and a part of the void in the concave of the continuous underground wall remains.

When the construction is completed and the water level of the water leakage from the continuous underground wall is restored, the concave portion of the continuous underground wall is filled with the water leakage,
The outside of the tarpaulin will be constantly exposed to water,
A waterproof sheet, particularly a polypropylene sheet as a core material, has high water resistance, retains its mechanical strength even in water for a long time, and maintains the performance as a waterproof sheet semipermanently. Therefore, it is possible to form a waterproof layer while leaving irregularities and steps on the surface of the continuous underground wall, eliminating the need for smoothing the surface of the continuous underground wall as in the past, reducing the cost of construction and shortening the construction period. Bring.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a longitudinal sectional view showing a state in which a waterproof layer is formed on the surface of a continuous underground wall according to the present invention, and a secondary lining reinforced concrete is constructed inside, and FIG. 1B is used. It is sectional drawing which shows an example of a waterproof sheet.

FIG. 2 shows a state in which the waterproof sheet is fixed to the surface of the continuous underground wall, (a) is an elevation view, and (b) is a cross-sectional view.

As the core material of the waterproof sheet, tensile strength = 42
0 (kg / cm ² ), elongation = 700 (%), tensile modulus = 14000 (kg / c
m ² ), compressive strength = 562 (kg / cm ² ), bending strength = 540 (kg / c
m ² ), using a polypropylene sheet with a thickness of 1 mm,
For rubber asphalt, 88 parts of asphalt, SBR
Using a blend of 12 parts of synthetic rubber and 2 parts of turpentine resin, a polypropylene sheet is laminated on both sides to a thickness of 1 mm on both sides to form a waterproof sheet.

According to JIS A60,
The values measured by the method according to No. 13 are as follows. Tensile strength: length 42.0 (kg / cm), width 31.0 (kg / cm) Elongation: length 690 (%), width 700 (%) Tear strength: length 14.0 (kg), width 12.0 (kg) As shown in (b), the waterproof sheet 2 is a three-layer laminate in which rubber asphalts 7 and 7 are respectively laminated on both sides of a polypropylene sheet 7 as a core material. A release paper 9 is attached to the entire surface, and a release paper 9 'is attached to the lap joint at the end on the secondary lining concrete side. The remaining part on the side of the secondary lining concrete is covered with sand.

A waterproof sheet 2 having a width of about 1 to 2 m and a length corresponding to the height of the continuous underground wall 1 is prepared as a single roll.

The operation of forming the waterproof layer according to the present invention is performed as follows.

(1) The end of the waterproof sheet 2 is fixed to the upper end surface of the continuous underground wall 1 with the nail 3. While unrolling the roll-shaped waterproof sheet 2 and removing the release paper 9 on the continuous underground wall 1 side, nails and tacks are struck in some places.
Is attached to the continuous underground wall 1. When the first one-turn waterproof sheet 2 is attached, the next one-turn waterproof sheet 2 is attached to the continuous underground wall 1 in the same manner, and this is repeated to fix the waterproof sheet 2 on the entire continuous underground wall 1. . The joint between the waterproof sheets 2 is a lap joint. Therefore, when the subsequent waterproof sheet 2 is attached to the continuous underground wall 1, the release paper 9 on the continuous underground wall 1 side of the subsequent waterproof sheet 2 is removed, and at the same time, the overlapping joint of the preceding waterproof sheet 2 is removed. Part of release paper 9 '
Is removed, the adhesive surface is exposed, and the ends of both waterproof sheets 2 are overlapped and joined. At this time, it is preferable to heat the overlapping portion using a burner or the like.

Since the waterproof sheet 2 is poor in flexibility and large and small irregularities remain on the outside thereof, a force for bending the lap joint portion inwardly acts by the casting pressure of concrete to be cast later. Then, there is a possibility that the adhesiveness of the joint is peeled off.

In order to prevent this, as shown in FIG. 2, it is preferable to adhere a strong adhesive tape 4 to the terminal of the overlapped joint.

(2) When the waterproof sheet 2 is attached to the continuous underground wall 1, the formwork is assembled and the reinforcing bars are arranged inside the waterproof sheet 2 as usual, and then concrete is poured. The waterproof sheet 2 is completely integrated with the secondary lining concrete 5 by the action of the sand 10 on the surface.

[0035]

According to the present invention, a laminated body in which a polypropylene-based sheet having a thickness of 0.6 to 2 mm is used as a core material and rubber asphalt is laminated on both surfaces thereof as an adhesive and a cushioning material is used as a waterproof sheet to provide a continuous underground. It is possible to form the waterproof layer while leaving irregularities and steps on the wall surface, and it is not necessary to smooth the continuous underground wall surface as in the related art, thereby reducing the construction cost and shortening the construction period.

[Brief description of the drawings]

FIG. 1 (a) is a longitudinal sectional view showing a state in which a waterproof layer is formed on the surface of a continuous underground wall according to the present invention, and secondary reinforced reinforced concrete is constructed inside, and FIG. 1 (b) is a sectional view of a waterproof sheet used. It is sectional drawing which shows an example.

FIGS. 2A and 2B show a state in which a waterproof sheet is fixed to the surface of a continuous underground wall, wherein FIG. 2A is an elevation view and FIG.

[Explanation of symbols]

1 ... continuous underground wall, 2 ... waterproof sheet, 3 ... nail, 4 ...
-Holding tape, 5-Secondary reinforced concrete, 6-
・ Concave section of continuous underground wall surface, 7 ・ ・ Polypropylene sheet, 8 ・ ・ Rubber asphalt, 9,9 ′ ・ ・ Release paper, 1
0.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshitaka Okazaki 4071-32 Leapto, Hasuda City, Saitama Prefecture (72) Inventor Keizo Yamaguchi 4-24-2 Shimosueyoshi, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Kisao Tanaka Tokyo 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo Inside Showa Shell Sekiyu KK (56) References JP-A-6-240661 (JP, A) JP-A-61-2553 (JP, U) Patent 2672472 (JP, B2) (58) Field surveyed (Int.Cl. ⁶ , DB name) E02D 5/02-5/20 E02D 29/00 E02D 29/045-29/055 E02D 31/02

Claims (1)

(57) [Claims] 1. A waterproof sheet comprising a high strength polypropylene sheet having a thickness of 0.6 to 2 mm as a core material and rubber asphalt having a thickness of about 1 mm laminated on both sides thereof is fixed to the surface of a continuous underground wall. A method for forming a waterproof layer on a continuous underground wall, comprising placing concrete for secondary lining on a surface of a waterproof sheet.